Fishing The Fly Scotland
Index => Rivers & Lochs => Topic started by: Hamish Young on 02/01/2015 at 12:29
-
OK, I am officially a wee bit confuddled.....
Sitting on the throne last night I picked up the most recent copy of FF&FT and found myself on Brucies page. In that spread was a piece on the electro-tagging of some 'larger' trout done on the Deveron (actually in a tributary of the Deveron) with the purpose being to track their movements over the space of a year.
Genuinely it is quite interesting.... but..... I thought it was common knowledge that 'larger' brownies tend to be somewhat migratory within the rivers of our part of the world (I include the Hydro rivers up here in Inverness-shire), opportunistically feeding on what's best available throughout the river system. Certainly it's been my view for some time - since moving to Aberdeenshire in the '90s anyway.
In Brucies piece this migratory activity appears as something of a revelation - but is it :? Not in my book.
Now why have I posted this in the Don section :? Well, it is my experience that larger browns are very much migratory on the Don. Sometimes better fish appearing in 'odd' places because of river height conditions (ie. trapped by lower water well upstream).
I thought this was common knowledge by most Don anglers.... is it ???
-
I thought this was common knowledge by most Don anglers.... is it ???
It is with this one :z16
Cheers
Sandy
-
The Don bailiffs regularly tagged large brown trout while catching salmon for the hatchery in their fish trap at Strathdon. It was regularly proved that these big trout ran up to Strathdon, even from the lower reaches of the river.
-
Yes, that has always been my experience on the Don Hamish :z16
Cheers
Mike
-
Hmmm not as common a perception as you'd think Hamish.
I've completed a bigger article on it for next month.
Been working with the MFTI guys for over two years now and the research actually throws up more questions than answers.
The main thing it really highlights is just how much we take our resident trout for granted.
If we don't look after 'em then we all know what can happen, yes it would take something catastrophic to end it all, however this already has in many places (the most recent is the confirmation of pike having been introduced to Lochindorb. Yes the fishing will get really good for a few years before the inevitable and this water ends up the same as Morlich, Garry, Callatter, Rosque etc)
-
Very interesting. I had no idea about this. Also, Lochindorb is one of the waters I intended fishing in 2015. Is it still worth a visit now there are pike in it?
-
Hmmm not as common a perception as you'd think Hamish.
That's what intrigues me Allan, where do people think they've come from if not elsewhere in the system :? :! I have the benefit of an educational grounding in fisheries management I suppose but it struck me very early on in my Aberdeenshire residency that there was no way the big browns we used to see on the Colquhonnies waters of the Don were 'resident' but were in fact itinerant and feeding opportunistically throughout the river. Of course I had no real way to prove the theory then; but the more anglers I spoke to the more plausible it appeared to be. Essentially all I did was apply knowledge I already had on the feeding behaviour of larger trout on loch systems (especially Loch Shiel) and applied it to a river and bingo presto hey what do you know :? It was a logical deduction to make and I am surprised - very surprised - that it's perhaps not one most anglers would make who fish a river in the north for trout regularly.
I'm genuinely interested in the work and I very much look forward to seeing a more comprehensive article :z16
Shocked to hear some retard has put Pike in to Lochindorb :mad
H
-
Bob Wyatt wrote somewhere about fish running up the Lonan burn from Loch Assynt in a spate to feed and dropping back when the water dropped.
-
with mixed spawning between brownies and sea trout would they move up steam together or simply pair up on the spawning redds. :z8 :z8
-
Potentially, both :z16
-
That's what intrigues me Allan, where do people think they've come from if not elsewhere in the system :? :! I have the benefit of an educational grounding in fisheries management I suppose but it struck me very early on in my Aberdeenshire residency that there was no way the big browns we used to see on the Colquhonnies waters of the Don were 'resident' but were in fact itinerant and feeding opportunistically throughout the river. Of course I had no real way to prove the theory then; but the more anglers I spoke to the more plausible it appeared to be. Essentially all I did was apply knowledge I already had on the feeding behaviour of larger trout on loch systems (especially Loch Shiel) and applied it to a river and bingo presto hey what do you know :? It was a logical deduction to make and I am surprised - very surprised - that it's perhaps not one most anglers would make who fish a river in the north for trout regularly.
I'm genuinely interested in the work and I very much look forward to seeing a more comprehensive article :z16
Shocked to hear some retard has put Pike in to Lochindorb :mad
H
A background almost everyone else doesn't have H and you are very correct in your assessment. I've followed this theory for a long time with no real way of proving. Common perception is that big trout will take up the best positions and exploit it, add to this the thinking that they are always there and will come onto the feed as required. EG 'There's a big fish under that tree / in that back eddy.' We've all heard this and given the right conditions this will most likely be the case. Essentially though just because big fish were in a given bit of water one day doesn't mean they're there the next and the Deveron work is helping prove this. I'll say more once my piece comes out.
-
Bob Wyatt wrote somewhere about fish running up the Lonan burn from Loch Assynt in a spate to feed and dropping back when the water dropped.
Happens in a lot of our water all the time Peter, why do you think I fish way up in the head waters in big water? Also waters that run in / out of lochs offer the opportunity to the Stillwater trout to test out the streams, similar to sea trout movements in and out rivers from the sea, as well as the opportunity to feed in these burns. I've encountered big numbers of fish more than ten miles from a loch that were simply not there before and are gone again directly after a spate.
-
with mixed spawning between brownies and sea trout would they move up steam together or simply pair up on the spawning redds. :z8 :z8
What's the difference between a sea going brown and a resident in fresh water? About a fortnight :wink
-
Aberdeen Uni did some radio tagging of Trout on the Don in the 90's. There must be something written down somewhere?? One of the students at the time was a member of the Grampian Pikers and had photos of some very big Don brownies taken well upriver. They also did surveys on Kinord, Davan and possible Skene.
For years I fished, walked and "snorkeled" a tiny burn in Angus. I could jump across most of it and the biggest "pool" was around 6 feet deep in normal conditions and perhaps 20 feet long. Real "worming" water and a great pool to lay in with a wetsuit and goggles and watch the trout.
75% of the time the Brownies were 3-6" long and could be seen as clear as day. However, towards October, these fish seemed to melt away, to be replaced by big headed "monsters" of around 20-24".
I had always thought that these bigger fish had moved up from the main river (Lunan) to spawn and possibly feed on the smaller brownies. As the spring came, the bigger fish left and the smaller ones appeared as if by magic.
On the issue of Pike and Lochindorb, it surprises me that the existence of Pike had been "confirmed" as I had been informed of pike being present by members of the RAF Kinloss angling club way back in the late 1980's who fished it both for trout and pike.
-
News to me and I fished with all the Kinloss guys throughout all the 90's and early 2000's when I ran the Moray Fly Fishing League but might be true, however I do know they fished Morlich, Laggan, Insch and Garve for both species.
Local scientists suspect they've been in around ten years, introduced possibly from the Aviemore area. Whatever the case then it means the trout fishing will get really good before the biomass tips in favour of pike and trout fall into minority, exactly the same as the other waters where pike have been introduced (Skene, Morlich, Garve, Callatter, Alvie, Insh, Achnalalt etc) unless some form of management of the pike takes place. Sadly as the loch isn't run as a trout fishery anymore then it'll simply be left to fate and time to dictate now.
Pike are a magnificent fish there's no denying this, and a species I like to catch, however there's also no denying that selfishness, greed and ignorance are the actions of those who illegally introduce them to waters where they didn't exist before. After all do we not have enough easily accessible and well spread pike venues already without adding more?
Why don't we stick grayling in the Don, Deveron, Spey and Dee to see what the outcome would be? You'd be guaranteed world class grayling fishing that's for sure but I bet you would get a far bigger reaction to this than that of someone putting pike into a wild trout loch. Sadly the outcome is very different, grayling would co-exist to no real detrimental effect on both resident or migratory stocks, pike on the other hand...............
-
Firstly I have to state once more that the illegal stocking of any species is wrong, both morally and legally.
Secondly I am not going to enter into a pro pike argument, contrary to popular belief, I do not believe that Pike should be stocked into wild waters and I do not believe Pike have preference over other species.
On the issue of biomass, there is more than enough research, evidence and proof that nature controls its own biomass and the only time if suffers is when man interferes or a natural disaster occurs.
On the issue of "why not stock grayling into the Don, Devron etc"...cast your mind back 10 years...Grayling were seen as vermin, killed by the salmon guys. In fact, it still goes on on some waters. However, Grayling would directly compete for food with other salmonoids and there is even some evidence to suggest they predate on Salmon eggs. BUT, they would find a natural balance is allowed to.
One last thought...The Dee, Don, Isla, Tay, Tummel, Spey and so on all have Pike swimming in them. Are they plagued with Pike that eat all the trout and salmon? No, because the active "management" of Pike does not take place these days (at least on no real scale). They have been allowed to reach a natural balance and certainly on the Tummel, Don and Isla the wild trout fishing is superb.
Again, I will state that the illegal stocking of any water with any species is wrong! I would also like to add that the "selflishness, greed and ignorance" of those that LEGALLY introduce Rainbow Trout into waters where they did not exist before "can" be just as damaging.
-
Aberdeen Uni did some radio tagging of Trout on the Don in the 90's.
This is interesting Rob, I hadn't heard of that before. Do any of the forum members know anyone who was involved with the project ??? I don't recall Jim Snr or Jnr mentioning it to me at any time, anyone else :z8 It's an absolute shame that important pieces of work which have been done in the past are often overlooked or forgotten about today, we should do better than that.
Could be some useful information in there at Aberdeen Uni tucked away in a darkened room or in the cupboard marked 'beware of the leopard' :z7
Back to the topic at hand, it would be of interest to me to see just exactly how many big broonies appear in the tributaries of the Don on/off during the season. Thinks..... :z17
H :cool:
-
Do any of the forum members know anyone who was involved with the project ???
I have been desperately trying to remember the chaps name! He later moved down south and did tagging for Barbel for the EA and was featured in Anglers Mail. I even remember seeing an online piece on him as he was making some interesting discoveries.
Leave it with me, I will dig through my emails...
There are online published results regarding Lochs Kinord and Davan done about the same time....if you can find them they might give you a contact name as he was involved with that to...as a student.
-
Was it Brian Shields? ..... Seems to ring a bell :z8
-
Was it Brian Shields? ..... Seems to ring a bell :z8
Not a name I recognize.....
However, the Aberdeen Uni survey of Kinord and Davan is listed as being done by Treasurer, Owen and Bowers, 1992. That might be a starter for ten if anyone has access to the Uni archives?
-
Just found some information on a study conducted on the Don in 1984 by "Mann, Mills and Crisp".
Interestingly this contains the only evidence I have found of Gudgeon on the Don, with an age range of 1-6 years in the samples caught. I bet a few Trout have grown big on these!
-
Back to the topic at hand, it would be of interest to me to see just exactly how many big broonies appear in the tributaries of the Don on/off during the season. Thinks..... :z17
H :cool:
Even more interesting if they can show if these trout are 100% fresh water resident fish or have spent a bit of time in the salt?
-
Firstly I have to state once more that the illegal stocking of any species is wrong, both morally and legally.
Secondly I am not going to enter into a pro pike argument, contrary to popular belief, I do not believe that Pike should be stocked into wild waters and I do not believe Pike have preference over other species.
On the issue of biomass, there is more than enough research, evidence and proof that nature controls its own biomass and the only time if suffers is when man interferes or a natural disaster occurs.
On the issue of "why not stock grayling into the Don, Devron etc"...cast your mind back 10 years...Grayling were seen as vermin, killed by the salmon guys. In fact, it still goes on on some waters. However, Grayling would directly compete for food with other salmonoids and there is even some evidence to suggest they predate on Salmon eggs. BUT, they would find a natural balance is allowed to.
One last thought...The Dee, Don, Isla, Tay, Tummel, Spey and so on all have Pike swimming in them. Are they plagued with Pike that eat all the trout and salmon? No, because the active "management" of Pike does not take place these days (at least on no real scale). They have been allowed to reach a natural balance and certainly on the Tummel, Don and Isla the wild trout fishing is superb.
Again, I will state that the illegal stocking of any water with any species is wrong! I would also like to add that the "selflishness, greed and ignorance" of those that LEGALLY introduce Rainbow Trout into waters where they did not exist before "can" be just as damaging.
Please don't think my previous reply was meant to provoke, merely tying to point out what's happened elsewhere, however in the interest of no hijacking a really interesting thread i'll simply end with this.
Agree on you reference to illegally stocked fish Rob especially when there is a danger that they might be fished for using other fish wich themselves may then be released into the given water.
Grayling were until recenty regarded as vermin widespread through the lower half of Scotland, thankfully a position that for the most part has changed and looks to continue that way. Sadly there are areas up here where our browns are regarded as vermin i'm afraid and will be / are removed given half a chance.
Finally the upper Spey does indeed hold pike (which i'm informed were intriduced late 60's?) and where the conditions suit have decimated the resident trout populations as well as have had an impact on migratory fish (especially migrating smolts). Agree that nature will find a balance but where conditions are favourable the balance will be 90% pike, 10% trout or thereabouts.
Anyway lets get back to the topic at hand migratory browns.
I'll ask the Moray Firth Trout Initiative guys if they've anything from the Don taging project or know where we can possibly look for it.
-
Agree that nature will find a balance but where conditions are favourable the balance will be 90% pike, 10% trout or thereabouts.
I am really sorry, but those figures are not supported by the scientific findings. There have been extensive studies done on this all over the Northern hemisphere, and without fail, the predator always remained in the minority.
Please review the extract below from a report produced by Dr. B. Broughton B.Sc. (Hons), Ph.D., F.I.F.M.
Prof. B. Rickards B.Sc., M.A., Ph.D., Sc.D, D.Sc, C.Geol., F.G.S., N. Fickling B.Sc. (Hons), M.Phil, I.F.M. Dip., D. Lumb B.A. (Hons) and C. Leibbrandt.
(Sorry for the large cut and past, but I only have a word document, no link to the report online...)
iv. Natural Balance
The data from numerous sources demonstrate that on stable fisheries there is a weight-to-weight
relationship between predatory fish and the prey which are available to them. This finding is in direct
agreement with the original assertion of Johnson (1949) and the detailed pond experiments conducted by
Swingle (1950). The studies on the status of the ponds, either balanced or unbalanced, revealed that the
predator/prey ratio, by weight, of balanced ponds was between 1:1.4 to 1:10. The studies showed that
77% of the best ‘balanced’ populations had ratios between 1:1.3 and 1:1.6.
Conversely ‘unbalanced’ populations had ratios of between 1:0.06 and 1:63. Most unbalanced populations
had a relatively small weight of predators in relation to the weight of prey. It appears that the weight of prey
present is a function of the fertility of the water, whereas the weight of predators is, within limits,
dependent on the weight of prey.
Since the results of these studies were published it has been confirmed that in most established fisheries in
Britain, the ratio, by weight, between pike and their prey is approximately 1:10. This has been determined
from the results of hundreds of counts of fish following the complete de-watering of fisheries or total fish
mortalities and the findings have been confirmed by fish population studies using seine nets, electro fishing,
traps etc.
In his review of a large quantity of data derived from eastern European predator fisheries, Popova (1967)
cites pike biomasses of 10-13 per cent of that of their available prey; Kell (1985) lists survey data for the
Sixteen Foot drain which give a relationship of 12 per cent; and Templeton (1995) recommends that pike
fisheries should be stocked with prey fish at a weight of eight times that of the pike. When Broughton
(unpublished data) analysed the catch statistics from several hundred scientific surveys of still and running
water fisheries in the English Midlands, an average weight ratio between pike and their available prey was
found to be approximately 1:10.
Using the ratio of 1:10, one can predict that 300lb of prey fish would be able to support some 30lb of pike
without any long-term, adverse effects on the abundance of either type of fish. A useful analogy is to imagine that the prey fish represent a sum of money which is invested. In effect, pike are consuming the
interest, leaving the capital sum untouched.
This balance is a so-called dynamic equilibrium - in other words, it will swing one way or another in
response to entirely natural phenomena (such as spawning success or outbreaks of disease). Equally, if
the balance swings markedly in favour of one 'side', ecological pressures ensure that eventually it will
swing back in the other direction (described in detail by Carlander 1958 and Anderson & Weithman 1978).
If this were not the case, there would be countless examples of fisheries in which pike have become
dominant or have totally eradicated the stocks of prey fish, and this would be a continuing situation on
unmanaged waters. We have reviewed a huge volume of the published scientific literature on pike in the
British Isles, Europe, North America and elsewhere, and there appears to be just one example where pike
had 'eaten themselves out of house and home' (Munro 1957).
Ricker (1952) described three types of numerical relationships between predatory fish and their prey. Mann
(1982), Kell (1985) and other authors have concluded that pike probably fall into Ricker's Type B model, in
which: "Predators at any given abundance take a fixed fraction of prey species present, as though there
were captures at random encounters". This means that predation is dependant on the numbers of prey,
rather than the numbers of predators.
Because of the annual production of fish flesh within a fishery as a result of spawning and growth, there is
little danger of pike consuming a large percentage of the potential prey fish. They will, in fact, consume some
of the surplus fish flesh produced each year, ensuring that the weight of both predators and prey remains
in balance.
-
What a super topic! I think Dryflee is right about this actually because while prey does indeed control predator in the case of pike it's not that simple because they are both prey and predator. I have read that the main food of large pike is small pike so it is perfectly possible for pike to almost eliminate all other species but still maintain a large population by feeding off each other.
-
What a super topic! I think Dryflee is right about this actually because while prey does indeed control predator in the case of pike it's not that simple because they are both prey and predator. I have read that the main food of large pike is small pike so it is perfectly possible for pike to almost eliminate all other species but still maintain a large population by feeding off each other.
Happy to accept this Simon, but you'd need to site some studies supporting this. Saying "I've read that..." is fine but you need to provide references. All the studies Rob sites seem to contradict your statement.
More pertinent to the argument is whether there is any information about the impact of pike introductions on the balance of different prey species in a water. You could, for instance, maintain a constant biomass of prey species but within that see one prey species (initially) heavily predated and replaced with another?
Should say that, as with everyone else, I'm against any unofficial/illegal stocking of any species.
-
Ok you've pressed me into one final reply Rob; how do you explain the decemation of natural trout stocks on waters where they were once prolific as a direct result of pike introduction? I don't mean a slight drop as per your 1:10 figures i mean the actual fact that trout are quite simply not there.
Accepting the possibility that these fish had altered feeding and behaviour patterns as a result of the sudden and increasing appearance of a highly efficient predator, but when looked at further waters such as Callatter (previously listed as similar trout population to Lochindorb and where estate thought it good practice to introduce pike in a bid to reduce trout numbers hence increasing size and quality of sport, noting also that this water isn't the only example you could site here) demostrate an almost total elimination of the previous residents. However if you then check the feeding streams large enough to sustain trout populations, these are found to be healthy in terms of trout numbers (Loch Luichart) eleminating the possibility of other explanation for the trout demise in the loch.
Yup totally agree Will and you're correct (as Simon notes also) that it is possible for a water to have the original population of fish replaced by a predator who then maintain their existance by feeding on each other. The evidence we have for this in terms of pike indicate that initially there were a few really large pike only for this to level out some time later into a much smaller but much more prolific average size (with obviously a few still in the Rod Bender range). In essence exactly the same result as we've seen where trout have been introduced into 'virgin' waters and left to their own devices.
Guys i'm sorry but we have actual real practical examples covering a multitude of time ranges (Callatter being the earliest i know, Spey system more recent, Lochindorb probably the most recent of all) where we can clearly see the devastating effect on the trout population from pike introduction is all i'm saying.
-
Even more interesting if they can show if these trout are 100% fresh water resident fish or have spent a bit of time in the salt?
You know my feelings on the subject.... if your memory is good think back to that day of 'trout' discussion on Watten a few years back :wink
H :cool:
-
Guys i'm sorry but we have actual real practical examples covering a multitude of time ranges (Callatter being the earliest i know, Spey system more recent, Lochindorb probably the most recent of all) where we can clearly see the devastating effect on the trout population from pike introduction is all i'm saying.
Chaps I'm not aiming this at any one poster (I know Allan, I have quoted you but this is amied at all posters in this thread) but we stand a chance of diverging so far from the original topic as to make the thread title pointless. Can we please keep this thread about the vagaries of trout residence/migration and leave the Pike to themselves .....in another thread if required :?
I appreciate that there's interest and relevance, but let's keep it in another thread. I'd rather not moderate unless I must :!
Cheers :z16
H :wink
-
Yup sorry Hamish, if there's a feeling the pike discussion needs to continue (although i've said all i want to about it) then someone could simply start a new thread?
Anyway back to to the original subject, when were we on Watten?? :z4 :z4
I'll keep the rest of my powder dry until my wee script comes out hopefully next month or the one after.
-
Hi All,
An interesting thread . My take on big brownies (anywhere) is that they did not get that way feeding on insects. Much the same as any fish, to build protein they have to eat protein . I suspect that many of the bigger river trout are predominantly fish eaters but also of course opportunistic , ( hence the reason we catch them on artificial flies occasionally). Perhaps these bigger fish roam to find suitable prey items ? and perhaps that roaming even gets them as far as the sea ( or local estuary) ? Do we have any data from scale readings which show sea feeding ( or other growth spurts) , in these large river brownies ?
PS: nice to be back :-)
-
insects are very high in protean :wink
-
Hi Marc,
:-)
:X2
-
"Taking The Initiative" ..... Nice article by Dryflee Allan related to this topic in this month's FF&FT Magazine :cool:
Cheers
Mike
-
Thanks Mike didn't realise it was out so early.
-
finally caught up with FF&FT backlog.
Trying to review the movements of the fish whose movements are featured in the article. She moved down to the very lower river (after spawning) in November, then hung around there until July. Then it moved fairly quickly up to mid-river, and stayed there for 3 months.
It would be fascinating to see data on day to day movements while she was at those two areas for prolonged periods. I guess you would need tens of receivers to track fish movements that way. Or a very determined person with polaroids.
-
I guess you would need tens of receivers to track fish movements that way. Or a very determined person with polaroids.
A hand held receiver can be employed as used on the Don. If I remember it has a range of about 100m and it is a case of starting below the last known location and walking until you locate the fish. I thinks a few long walks might be required with some fish :)
-
When you say upper and lower parts of the river how far would the fish be moving in terms of miles
-
I too finally got to read the piece today :z18
Great information, backing up a lot of what i've believed for a long time,
very surprised with the timing as well, but just goes to show what actual evidence and not just anecdotes can provide.
I've always thought that good fish are found in good holding spots and it is not necessarily the same fish each time you try for it, this goes some way to support that idea :z18
Makes you think about wading at the end of the season though, if the trout have spawned then i'd be mortified to think i was disturbing their redds. One to bear in mind from now on :z16
Sandy
-
Thanks Sandy :z16
Hand helds are very much a hit or miss Rob, much better are fixed receivers, although given the extremely high cost of the transmitters and the fact that they have to be surgically fitted to the fish (which holds an obvious danger to the trout well beyond the debate of why lift it out the water for a photo) means this will always be a limited exercise.
Iain the data gathered suggested that the fish in question was indeed moving daily to feed and knowing the bit of water in question it would appear (also given the time of year) that this fish was moving into areas where the best upwing hatches were.
If you take this as an indication of a number of the fish in the system then it would support the theory that they will move some surprising distances to take advantage of the best feeding bits and not necessarily hold in the same spot but range between a number of them. So yes a big fish might be found in a given location but no a big fish always lives there.
-
I don't know about migratory browns on the west here, but there is some anecdotal evidence that the bigger char in one system move between lochs, not just to spawn, these are char that have been seen, at around 2 1/2 lb, moving through a 3 loch system,with a 4 mile river, so migratory browns in a similar situation would not be unusual, and the don is a decent sized system,easgach 1
-
I don't know about migratory browns on the west here
In my experience it's much much more common than some folk would believe.
, but there is some anecdotal evidence that the bigger char in one system move between lochs, not just to spawn, these are char that have been seen, at around 2 1/2 lb, moving through a 3 loch system,with a 4 mile river, so migratory browns in a similar situation would not be unusual, and the don is a decent sized system,easgach 1
See Char moving about in the Garry system, so I can believe they do migrate between waters.
H
-
Hi Hamish,
I would agree with you there ,not only on the West coast :wink
Alan is the data mentioned in your article going to be written up in the form of a scientific paper. If so I would be much obliged for the reference details.
Thanks.
Paul.
-
Already is Paul, will get the ref to you, however meantime if you look at the MFTI website you'll get more background info.
Cheers
Allan
-
Thanks Allan, will do .
Cheers.
Paul.